This repository is created for the Microcontrollers 5 course in semester 6 (3rd year) of my Embedded Systems Engineering Bachelor program. It contains a modified codebase that is part of the semester 6 (projectname: HealthBot) project on Social Robotics I also work on (For HAN Health Concept Lab). This separate repository focuses on demonstrating FreeRTOS primary highlights and concepts for the course assessment.
The course focused on Embedded RTOS concepts and applications. For the final assessment, students were required to implement their own Embedded RTOS-based system (using FreeRTOS, Zephyr, TI-RTOS, VxWorks, etc.). I chose FreeRTOS and the Raspberry Pi Pico, which I also used in my semester 6 project. This codebase is a FreeRTOS-specialized version of the semester 6 firmware development project. It includes specific application logic to better illustrate FreeRTOS features.
The program, while not performing any real-world useful functions, serves as a demonstrative implementation of FreeRTOS with developed drivers. Ultimately, this codebase is used in the creation of a social robot aimed at entertaining the elderly.
The presented repository is graded with a 8.6 by the course teacher (Ewout Boks). The assessment was based on the following things:
- Description of scheduling techniques
- Description of inter-task communication
- Source code Quality (structural)
- Documented RTOS Configuration
- High Level Design (Architecture)
- Test Scenarios
For each sections between 0 and 3 points could be obtained, and the grade is given by: Grade = (\frac{\sum \text{Scores per assessment criterion}}{3 \times \text{Number of criteria}} \times 10)
This project builds upon previous display firmware, adding motor control on the Raspberry Pi Pico W microcontroller. The system integrates various drivers and utilizes FreeRTOS to manage concurrent tasks effectively.
The diagram illustrates the embedded system's architecture centered around a microcontroller unit (MCU). Key components include:
- MCU (Microcontroller Unit): Manages all peripherals and interfaces.
- mmWave RADAR: Connected via SPI for device control.
- SW Array (Switch Array): Inputs data to the MCU, for event groups demonstration.
- Serial Port: Facilitates UART communication for debugging and data exchange.
- Speaker: Outputs audio via PDM (Pulsed Audio).
- Step Motor: Step Motor controlled via step, direction, and enable signals for precise movement.
- LEDs: Indicate status of the event group's bits set by the buttons.
- Display: Managed over SPI for user interface display.
- DB Port (Debug Port): Used for system diagnostics and programming.
This setup demonstrates the MCU's role as a central hub, coordinating input/output devices and managing data flow in a potentially real-time operating system environment.
- Stepper Motor Driver: Implementation for controlling a stepper motor.
- UART Asynchronous Communication: Driver for UART communication without blocking the main execution flow.
- PWM Audio Output: Controller for audio output using Pulse Width Modulation.
- Dual-Core Functionality: Utilization of both cores on the Pico W for improved performance and task distribution.
- Display Control: Management of display tasks using the LVGL library. FreeRTOS Concepts
- Software Timers: Timer services for delayed and periodic execution of functions.
- Task Wake-Up from ISR: Use of xHigherPriorityTaskWoken to manage task wake-ups from interrupt service routines.
- Deferred Interrupt Handling: Deferring work to the RTOS daemon task for processing outside of interrupt context.
- Semaphores and Mutexes: Synchronization primitives for managing resource access and task coordination.
- Event Groups: Mechanism for task synchronization based on events.
- Logic Analyzer: System signals were tested using a logic analyzer to verify timing and signal integrity.
- TTL Module: External UART communication was tested using a TTL module to ensure reliable data transmission.
- JLink Edu Mini Debugger: Various system scenarios were verified using the JLink Edu Mini debugger and serial prints for real-time debugging and validation.
For more details, like the test description, performance analysis and other technical specifics check the MIC5-REPORT